The world is currently experiencing revolutionary changes in communications systems, brought about, in part, by the evolution of the Internet. Conventional communications systems, however, such as the Public Switched Telephone Network (PSTN), are also undergoing revolutionary changes to bring enhanced services to subscribers.
Intelligent Network (IN) services refers generally to a collection of services offered to PSTN telephony system subscribers on a pre-subscribed basis, such as Calling Number Delivery, Calling Number Blocking, Customer Originated Trace, Automatic Recall, Automatic Callback, Selective Call Forwarding, Call Waiting, Selective Call Waiting, Selective Call Rejection, and Selective Call Acceptance. The collection of IN services is continually growing as telecommunications system engineers devise both improved and novel systems and processes for providing advanced services. The medium for providing communications services, however, is gradually transitioning from the circuit-switched PSTN networks to packet-switched networks, such as the Internet, and, thus, it is desirable to provide similar services in packet-switched communications environments.
One particularly popular IN service is Call Waiting. If a subscriber to the service is engaged in a call, and a call from another party is received, the subscriber receives an indication, such as an audible tone. The subscriber can, if desired, place the first call on hold and connect to the second call. After connecting to the second call, the subscriber can then alternate between the first and second calls, as desired. Although the Call Waiting IN services has become very popular, it has the disadvantage of only allowing a subscriber to communicate with one calling party at a time. For example, if, after connecting to the second call, the subscriber desires to tell the first caller that the subscriber needs to continue with the second call, the subscriber must place the second call on hold to reconnect to the first call, inform the first caller of this need, and then reconnect to the second call. This may be undesirable if, for example, the second call is long distance, extremely urgent, or the subscriber doesn't wish the second caller to know that the subscriber was on another call.
Accordingly, there is a need in the art for methods for providing an enhanced Call Waiting service that allows a subscriber to communicate with a first calling party without interrupting communications with a second calling party. There is a further need in the art for providing such enhanced Call Waiting service within a packet-switched communications network, such as the Internet.